1220251566 has 8 divisors (see below), whose sum is σ = 2440503144. Its totient is φ = 406750520.

The previous prime is 1220251559. The next prime is 1220251577. The reversal of 1220251566 is 6651520221.

It is a sphenic number, since it is the product of 3 distinct primes.

1220251566 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101687625 + ... + 101687636.

It is an arithmetic number, because the mean of its divisors is an integer number (305062893).

Almost surely, 2^1220251566 is an apocalyptic number.

1220251566 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1220251566 is a wasteful number, since it uses less digits than its factorization.

1220251566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203375266.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 1220251566 is about 34932.0993643382. The cubic root of 1220251566 is about 1068.6031692954.

Adding to 1220251566 its reverse (6651520221), we get a palindrome (7871771787).

The spelling of 1220251566 in words is "one billion, two hundred twenty million, two hundred fifty-one thousand, five hundred sixty-six".